Horton

Re: another autovacuum scheduling thread

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Sami Imseih <samimseih@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Jeremy Schneider <schneider@ardentperf.com>, pgsql-hackers@postgresql.org
Date: 2025-10-26T01:25:48Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add rudimentary table prioritization to autovacuum.

  2. Trigger more frequent autovacuums with relallfrozen

  3. Harden nbtree page deletion.

  4. Check for interrupts inside the nbtree page deletion code.

On Sat, 25 Oct 2025 at 04:08, Nathan Bossart <nathandbossart@gmail.com> wrote:
> Here is an updated patch based on the latest discussion.

Thanks. I've just had a look at it. A few comments and questions.

1) The subtraction here looks back to front:

+ xid_age = TransactionIdIsNormal(relfrozenxid) ? relfrozenxid - recentXid : 0;
+ mxid_age = MultiXactIdIsValid(relminmxid) ? relminmxid - recentMulti : 0;

2) Would it be better to move all the code that sets the xid_score and
mxid_score to under an "if (force_vacuum)"? Those two variables could
be declared in there too.

3) Could the following be refactored a bit so we only check the "relid
!= StatisticRelationId" condition once?

+ if (relid != StatisticRelationId &&
+ classForm->relkind != RELKIND_TOASTVALUE)

Something like:

/* ANALYZE refuses to work with pg_statistic and we don't analyze
toast tables */
if (anltuples > anlthresh && relid != StatisticRelationId &&
    classForm->relkind != RELKIND_TOASTVALUE)
{
    *doanalyze = true;
    // calc analyze score and Max with *score
}
else
  *doanalyze = false;

then delete:

/* ANALYZE refuses to work with pg_statistic */
if (relid == StatisticRelationId)
    *doanalyze = false;

4) Should these be TransactionIds?

+ uint32 xid_age;
+ uint32 mxid_age;

5) Instead of:

+ double score = 0.0;

Is it better to zero the score inside relation_needs_vacanalyze() so
it works the same as the other output parameters?

David